1. Field of the Invention
The present invention relates to a photographing apparatus, a method of controlling the same, and a recording medium having recorded thereon a computer program to implement the method. More particularly, the present invention relates to a photographing apparatus that is capable of minimizing an access bandwidth of memory included in the photographing apparatus and that is also capable of reducing power consumption, a method of controlling the photographing apparatus, and a recording medium having recorded thereon a computer program to implement the method.
2. Description of the Related Art
In current times, photographing apparatuses such as digital cameras are decreasing in size and are able to operate at a wider angle, which can increase distortion in edge regions of a captured image.
For example, Japanese Patent Publication No. 2005-011268 discloses technology for correcting distortion of images captured using a lens optical system by using a distortion correction circuit.
Meanwhile, digital zoom technology for increasing a magnification of an image obtained from an imaging device of a photographing apparatus such as a digital camera, by performing image processing on the image is well-known.
However, in the photographing apparatus, data read by the imaging device is initially stored in memory such as synchronous dynamic random access memory (SDRAM). The data is read from the SDRAM so as to undergo distortion correction, and then is re-stored in the SDRAM after the distortion correction is performed. Likewise, when digital zoom is performed, image data stored in the SDRAM is read, a magnified image is generated by performing image processing such as interpolation on the image data, and then the magnified image is re-stored in the SDRAM.
As such, data read and write operations from/into memory are frequently performed and thus a bandwidth for accessing the memory becomes insufficient. In particular, the distortion correction and the digital zoom are performed on uncompressed image data. As a result, an accessing bandwidth of memory becomes greatly insufficient. Also, in a small device, an access bandwidth of SDRAM is originally small and thus ensuring a sufficient access bandwidth becomes more difficult. Accordingly, a solution of, for example, operating a system clock at high speed is required and thus system configuration becomes complicated and power consumption is increased.
Also, photographing apparatuses such as digital cameras require higher speed processing in order to comply with high-vision video images and high-resolution display devices. In this situation, photographing apparatuses such as portable devices cannot easily increase a total frequency bandwidth of memory because an available frequency bandwidth of memory is limited and a bandwidth of a bus cannot be increased in consideration of manufacturing costs, and thus an access bandwidth of memory becomes greatly insufficient.